The present application relates generally to monitoring systems and, more particularly, to a method, device, and system for use in monitoring current provided to a load.
Known electrical distribution circuits include a plurality of switchgear or other circuit breakers that are coupled to one or more loads. The switchgear and/or circuit breakers typically include a trip mechanism that interrupts current flowing to the loads if the current exceeds a current threshold and/or if the current otherwise is outside of acceptable operating conditions.
At least some known circuit breakers and/or switchgear include a primary current transformer that measures the current flowing through the trip mechanism contacts. Such circuit breakers and/or switchgear may also include a self-powered electronic trip unit (ETU) that programmably activates the trip mechanism to interrupt the current provided to the load. Such self-powered ETUs typically include a secondary current transformer coupled in series with a power supply to monitor current and to electrically decouple the power supply from the electrical distribution circuits. However, the secondary current transformers may undesirably increase a cost and/or a size of the self-powered ETUs, and may also cause the ETUs to be more susceptible to noise as compared to ETUs that do not include the secondary current transformers.